[TEST] restored `gateway: local` settings in ClusterDiscoveryConfiguration fork and clarify version assert (now for real)

Local gateway has been removed in core, but it's a master only change. If we don't set it to local in our settings, we end up using the none gateway and KnownActionsTests fails because the local gateway endpoint are not registered to core.

Original commit: elastic/x-pack-elasticsearch@9bb550329f

src/test/java/org/elasticsearch/test/discovery/ClusterDiscoveryConfiguration.java

@@ -27,7 +27,7 @@ public class ClusterDiscoveryConfiguration extends SettingsSource {
     }
 
     static Settings DEFAULT_NODE_SETTINGS = ImmutableSettings.settingsBuilder()
-            //.put("gateway.type", "local")
+            .put("gateway.type", "local")
             .put("discovery.type", "zen").build();
 
     final int numOfNodes;